Mike Weighall ponders whether new emerging battery chemistries are likely to be disruptive and thus change the world.
Disruptive technology is technology that eventually overturns the dominance of existing technology or products in the market. It may dominate an existing market by filling a role that the older technology cannot fill; or successively move up-market through performance improvements and cost reductions until finally displacing the market incumbents.
Some examples of disruptive technology include the steam engine, internal combustion engine; semiconductors, digital photography, compact discs, VoIP phone technology, etc. All these technologies eventually displaced – or are in the process of displacing – the previous market incumbents. Compact discs, for example, are themselves being displaced by even newer technology, on-line downloads of music to computers, mp3 players and mobile phones.
It is interesting to speculate whether there is a new technology waiting in the wings that will have a similarly disruptive effect on the battery industry and such key markets as automotive, medical, and aerospace. Batteries are, of course, used in a wide range of applications and markets, each with their own specific requirements. For the purposes of this article, I have chosen to focus mainly on the automotive battery market. New battery technology (possibly combined with ultracapacitors) is needed to ensure the success of hybrid electric vehicles and plug-in hybrid electric vehicles. Our starting point is to see whether we can learn some lessons from a couple of recent examples of disruptive technology in the lead-acid battery industry.
Originally developed by Daramic, the PE separator market is now dominated by Daramic and Entek. Daramic began to supply the industry with PE separators in the early 1980s, and Entek entered the market with an improved, automated manufacturing process in 1987. In 1988 Entec joined with to form Cookson Group, with Entek providing the technology and Cookson the finance. Cookson Entek became responsible for the steady growth in the market for Entek’s PE separator outside North America. Entek took control of the joint venture in 1996, and in 1999 purchased Cookson’s equity to become sole controller of ENTEK International Limited. An interesting aspect of the formation of Cookson Entek in 1988 was that it took the battery industry by surprise. Although Cookson was supplying other products to the battery industry, they had no previous experience of the battery separator market (ref: BEST magazine July 2004 pp. 47-48).
When first introduced, polyethylene separators were technically superior to existing separator products for the SLI battery market, but with a price premium. Progressive technical and manufacturing improvements as the market developed resulted in significant price reductions. This meant that the polyethylene separator was able to compete with the incumbent products on price as well as on improved quality and technical benefits. As a result, PE separators now account for about 97% of the total worldwide market. In 2007, the total SLI battery market was about 380m units, and the total PE separator usage ~ 485m m2. Although there are now about 9 PE separator manufacturers worldwide, Daramic and Entek still dominate the market with about 51% and 37% market share respectively. This is a good example of how disruptive technology can displace existing incumbents in the marketplace. Initially, the higher cost of PE separators meant they had to be marketed on the basis of the technical benefits (improved performance, fewer defects etc.). As manufacturing costs decreased, the PC separator was able to compete with other alternatives on price as well as quality and performance.
The article by John Devitt in the Autumn 2007 issue of BEST magazine makes fascinating reading: particularly if one is thinking about disruptive technology. Here was another revolutionary product that did not come from the battery industry, but from a company better known for the manufacture of rubber belts and hoses (the Gates Rubber Company). The development of the microfine glass separator was, of course, a key factor in the successful development of the AGM type VRLA battery, but John Devitt and his team at Gates developed many other technical innovations as well. The VRLA battery has now become dominant in many standby power and motive power applications and is even starting to replace the conventional flooded lead-acid battery in some automotive applications. In the highly competitive automotive market, the higher price of the VRLA battery (higher materials and manufacturing costs, lower manufacturing volume), compared with the conventional lead-acid battery, has inhibited market growth to date. Heightened demands on batteries for automotive applications thus offer an excellent for advanced VRLA batteries to gain significant market share.
Europe, for example, has seen a trend toward the use of VRLA batteries for soft hybrids (start-stop etc.) Similarly, EU emissions target standards have driven replacement of flooded batteries. In the short term, installed capacity rather than the potential market may be limiting growth, as this is in the hands of only a small number of battery companies (JCI, Exide, Banner, Moll). BMW, Mercedes, and VW plan to convert their fleets to VRLA to meet legislated standards – assuming that the battery manufacturers can meet this growth in demand at a price acceptable to the vehicle manufacturers. At the moment, the supply base is probably only about 1.5m VRLA SLI batteries, from the 4 manufacturers mentioned above. There needs to be a significant increase in the installed capacity in order to take full advantage of the increased level of interest from the automotive manufacturers and the changes in vehicle technology (stop-start etc.).
I have drawn up a “short list” of some possible contenders:
• A123 Systems
• Firefly Energy advanced lead acid battery
• Axion Power e3 Supercell
• Atraverda bipolar lead acid battery
• CSIRO Ultrabattery
A123 Systems use iron phosphate instead of cobalt oxide in the positive electrode of their Lithium-ion chemistry. However, they’ve assembled the iron phosphate in a novel, nanoparticle structure in which the particles are 100 times smaller than conventional oxides and eight orders of magnitude more conductive than conventional phosphates. A123 Systems, located in Watertown, Massachusetts, is as remarkable for its brief history, entrepreneurial spirit and smart business acumen as it is for a technology revolutionary in energy, cost, and safety. Founded only six years ago, the company has accumulated $132 million in venture funding, six manufacturing plants in China, 852 carefully recruited employees, 120 patents, and the largest lithium-ion R&D team in North America (www.xcomony.com). They currently manufacture high-power lithium-ion batteries for Black & Decker, and have become one of the front-runners to supply lithium-ion batteries for GM’s Chevrolet Volt.
Another interesting development has come not from the battery industry but from Firefly Energy, a Caterpillar spin-off based in Peoria, Illinois. Caterpillar’s R & D programme resulted in the creation of the composite plate material that is at the heart of the Firefly Energy battery technology. While still based on the lead-acid battery, the new battery claims a number of technical benefits, including: extended life, lighter weight, higher active material utilisation, and a composite material that can be integrated into existing manufacturing processes, and that enables the battery to be recycled at the end of life. The battery’s PSoC (partial state of charge operation) also eliminates problems with sulphation of the negative plates.
Firefly, who intend is to license their technology to battery makers, already have contracts with North Star Battery and Crown Battery and a contract with the U.S. government. Their business model involves manufacturing the foam electrodes battery makers will use for assembly into finished batteries, which Firefly will then market.
The first batteries to reach the market will include the foam electrodes for the negative plates only (3D). The 3D2 battery – foam electrodes for both plates – is presumably taking longer to develop due to issues with oxidation of the foam positive electrode. I haven’t seen any recent published data concerning the performance of the 3D2 battery but it should be comparable to that of the current NiMH battery, presumably at a significantly lower cost. Unlike conventional lead-acid batteries, negative plate sulphation in PSoC operation (hybrid electric vehicle application) will not be a problem.
The Axion Power e3 Supercell is a hybrid battery/ultracapacitor in which the positive electrode is standard lead dioxide, while the negative electrode consists of activated carbon. The assembly process is very similar to that used in conventional lead-acid batteries. Axion Power, based in Newcastle Pennsylvania, purchased the former Newcastle Battery factory (complete with the existing skilled staff), where they build and test the prototype hybrid battery/ultracapacitors. Their data (below) compares the performance, life & cost of the e3 Supercell with that of other battery technologies as follows:
Axion Power are currently targeting multiple markets, including hybrid electric vehicles, grid connected power, power quality, motive power and renewable energy (wind & solar power). Ultimately, their intention is just supply the carbon plates to other battery manufacturers. Compared with conventional lead-acid batteries, they claim significant benefits, such as higher power densities, faster recharge rates, longer cycle lives in deep discharge applications, reduced premature failures (and warranty claims), 70% less lead, and sealed, maintenance free design.
Like Firefly Energy, the Atraverda battery is based on lead-acid technology, and uses Ebonex® – a proprietary titanium suboxide ceramic structure – for the grid. Atraverda uses this ceramic structure to build a bipolar battery, designed to be of the VRLA type with AGM separators. The Ebonex® plate is in a thermal plastic matrix, which avoids the problem of making a perfect seal to lead. The unpasted plate contains the Ebonex® particles in a polymer matrix, with a thin lead alloy foil on the external surfaces. Independent evaluations confirm performance data of 50 – 60 Wh/kg & 100 – 120 Wh/L.
Atraverda, who have no intention of becoming a battery manufacturer, are seeking to licence their technology to existing battery manufacturers. Their strategy is to supply the key components (the Ebonex® electrodes) that conventional battery manufacturers can incorporate into their existing production lines with very little modification. Based in the UK, they are currently working with East Penn Manufacturing Inc. in the USA, Exide Industries in India, and Vladar Enterprise Limited in the Ukraine.
The CSIRO Ultrabattery combines an asymmetric ultracapacitor and a lead acid battery in each cell. The company (Commonwealth Scientific and Industrial Research Organisation) claims that this utilises the best of both technologies without the need for extra electronic controls. The capacitor enhances the power and lifetime of the battery by acting as a buffer during charging and discharging. The technology has been licensed to the Furukawa Battery Co. Ltd. The Ultrabattery reportedly features a life cycle that is at least four times longer and produces 50% more power than conventional battery systems. It is also about 70% cheaper than the batteries currently used in HEVs.
CSIRO’s target market is the HEV application. In fact, Ultrabatteries are now undergoing road trials in a Honda Insight HEV prototype at the GM Millbrook Proving Ground in the UK as part of the ALABC Research Programme. Compared with conventional lead acid technology, the Ultrabatteries are expected to perform better in the partial state of charge duty cycle. The Ultrabatteries should also enable more efficient energy conversion during regenerative braking. The road trials have now reached a landmark 100,000 miles.
If this new hybrid battery/ultracapacitor is only half as good as the marketing hype, this really will be a prime candidate for disruptive technology. However because EEStor, based in Cedar Park, Texas, is a very secretive Company, it is very difficult to make a valid assessment of their technology. They are claiming a specific energy of up to 280 Wh/ kg, compared with around 120 Wh/ kg for Lithium-ion and 32 – 40 Wh/kg for lead-acid. My understanding is that the basis material is a high-permittivity composition-modified barium titanate ceramic powder. This powder is double-coated, the first coating being aluminium oxide and the second coating calcium magnesium aluminosilicate glass.
Currently I find insufficient data in the public domain to assess whether EEStor’s claims for this product are genuine. However, if successful, this new hybrid battery/ultracapacitor will compete with all energy storage systems (including lithium ion), not just ultracapacitors. Other technical experts have commented that because this is a ceramic system – and brittle by nature – thermal stresses could cause microfractures and ultimately failure. It is a high voltage system, and may self-discharge in hours rather than days. Concern has also been expressed about the low temperature performance. Industry experts are thus very sceptical, and reserving judgment until independently verified experimental data becomes available.
The reader is referred to John Miller’s excellent summary of the concerns about the EEStor Technology in the Winter 2008 issue of BEST magazine (pp. 145-146). As he notes, the main concerns about this product include the fact that it operates too close to breakdown voltage, its technology is not scalable, its ultracapacitors are not self-clearing, and its quoted charge times are not realistic.
In spite of these concerns, and the fact that so little information is in the public domain about EEStor, the product is attracting significant investment interest. Zenn Motors of Canada, an investor, wants to incorporate the batteries into its cars – but are still waiting for their first storage units. Kleiner Perkins Caufield & Byers are also reportedly potential investors. Lockheed Martin has signed a deal with EEStor to try to integrate the ultracapacitor start-up’s electrical energy storage units into the defence contractor’s products. During 2008, Lockheed will evaluate samples that it receives from EEStor.
For its Lithium-ion batteries, Altairnano, of Reno, Nevada, has developed and optimised nano-structured lithium titanate spinel oxide (LTO) electrode materials that replace the graphite electrode materials found in negative electrodes of current Li-ion batteries on the market. These have been combined with positive electrodes from conventional Lithium-ion batteries. In laboratory testing, power density as high as 4000 W/kg and 5000 W/L has been achieved. So far their market focus is the high power battery market, specifically in hybrid and electric vehicles. Phoenix Motors are planning to use Altairnano batteries for a small electric pickup, but Altair have supplied no batteries to them to date. Claimed benefits include faster charging and discharging, longer battery life, operation in extreme temperature conditions, and safe operating characteristics.
Disruptive technology may also come from existing major battery manufacturers, for example PEVE (Panasonic EV Energy), who already supply the nickel metal hydride batteries for the Toyota Prius, and are presumably working on an advanced lithium ion battery for a possible plug-in hybrid version of the Prius. However, existing manufacturers are often at a disadvantage in that new, potentially disruptive technology that they develop themselves may displace their own existing products rather than competitors’ products. For example, Daramic’s development of the Polyethylene separator has affected the market for existing DARAK separators (resin coated paper etc.).
Conventional ultracapacitors have a very high cycle life and high instantaneous power. However, the low specific energy and relatively high cost inhibits their use for many applications, such as automotive. The “hybrids” mentioned in this article (Axion Power, CSIRO) achieve a higher specific energy, but compromise with a lower cycle life and lower power. The lead-acid based battery technologies (Firefly Energy, Atraverda) achieve a higher specific energy than conventional lead-acid batteries, at a cost considerably lower than for NiMH or Li-ion battery systems.
The proposed application is also very important. For hybrid electric vehicles, the battery may be cycling at a partial state of charge within a very narrow range e.g. 50 – 60% SoC. This precludes the use of a conventional lead acid battery because of sulphation issues, but the Firefly Energy battery may be acceptable in this application. For plug-in hybrids, the battery will undergo regular deep discharge, so a long cycle life is essential. In fact – for a plug-in hybrid – a combination of an advanced battery and an advanced ultracapacitor or hybrid ultracapacitor may be the ideal solution. We may end up with not one but several disruptive technologies dependent on the market application. The battery requirements for consumer applications for example, are very different from those for the automotive industry. For the automotive industry, an improved battery may in itself help to drive the market for hybrid and plug-in hybrid electric vehicles.
In this article, for obvious reasons, I have only been able to review those battery technologies for which some information is already available. I have also, of necessity, had to leave out some of the possible battery options. The actual next disruptive battery technology could be something completely different from those I have reviewed. To quote a colleague, Morris Kindig of Tier One:
• What we know today is already history
• What is likely tomorrow is evolutionary…and predictable
• What is probable is still emerging
• What is revolutionary resides in the creative mind…
• in the garage across the town or the lab at the end of the hall.
Whatever the next disruptive technology for the battery industry turns out to be, I am sure that you will read about it here first.